diff --git a/db/upgrade.php b/db/upgrade.php
index 6920e69..6c75786 100644
--- a/db/upgrade.php
+++ b/db/upgrade.php
@@ -1547,7 +1547,7 @@ function xmldb_game_upgrade($oldversion) {
     
     if ($oldversion < ($ver = 2016062603)) {  
         $table = new xmldb_table('game_cross');
-        $field = new xmldb_field('createscore', XMLDB_TYPE_FLOAT, null, null, XMLDB_NOTNULL, null, '0');
+        $field = new xmldb_field('createscore', XMLDB_TYPE_FLOAT, null, null, XMLDB_NULL, null, '0');
 
         // Launch change of type for field thisfield
         $dbman->change_field_type($table, $field);